Fluid flow circuit breaker with cup-shaped actuator



March 8, 1966 B. H. CLASQN FLUID FLOW CIRCUIT BREAKER WITH CUP-SHAPED ACTUATOR 2 Sheets-Sheet 1 Filed Aug. 9, 1963 INVENTOR. Ber?!) H. C7450)? BY C W,W

H15 ATTORNEY March 8, 1966 B. H. CLASON Filed Aug. 9, 1963 FLUID FLOW CIRCUIT BREAKER WITH CUP-SHAPED ACTUATOR INVENTOR. Berzz') H. C/asozz H16 ATTORNEY United States Patent ()fiice 3,239,624 FLUID FLOW CIRCUIT BREAKER WITH CUP-SHAPED ACTUATOR Berti]! H. Clason, Flint, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Aug. 9, 1963, Ser. No. 301,154 7 Claims. (Cl. 280-81.9)

This invention relates to electrical switches and more particularly to a type of switch that is responsive to the flow of fluids.

It is an object of the present invention to provide a switch which can make or break an electrical circuit in response to the flow of fluid in a system in which the switch is mounted.

It is another object of the present invention to provide an electrical switch for mounting in a fluid system in which the switching mechanism is electrically insulated from the fluid it is monitoring.

It is a further object of the present invention to provide a fluid responsive circuit breaker that is simple in operation and inexpensive to manufacture.

It is yet a further object of the present invention to provide a fluid responsive flow switch which is responsive to the flow of fluid in any direction in a system in which the switch is mounted.

It is still a further object of the present invention to provide a switch that is responsive to a flow of water in a system where the switch is mounted in a water channel but where the current carrying portions of the switch are maintained moisture free.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is an enlarged sectional view of one embodiment of the present invention shown in a typical pumping circuit and connected to a typical electrical indicating circuit;

FIGURE 2 illustrates another embodiment of the subject device.

Referring now to FIGURE 1, a fluid flow circuit breaker, generally designated by the numeral 10, is located in a pumping circuit consisting of a sump 12, a pump 14 and circulation lines 16. A switch body 18 has a threaded portion 20 cooperating with a threaded tapped aperture 22 in aportion of the circulation line 16. A terminal 24 is electrically connected with a battery 26 through a switch 28 and an indicating light 30, one side of the battery going to ground as does the switch body 18.

The terminal 24 extends into one end of the switch body 18 and is insulated from said body by being mounted within an insulator plug 32. The insulator plug 32 is wedged between a flange 34 of the switch body 18 and a peened-over lip 36. A portion of the terminal 24 extends into the switch body and forms a fixed contact 38 therein. An actuator rod 40 has a contact 42 formed on one end thereof. The actuator rod 40 is disposed for slidable movement within an aperture 44 of the switch body 18 and has a beveled flange 46 hearing against an inside surface 48 of a cup-shaped actuator 50. The actua- 3,239,624 Patented Mar. 8, 1966 tor rod 40 has a spring retaining disk 52 upon which bears a spring 54. The spring 54 is slightly depressed between the spring retaining disk 52 and a slanted inside wall 56 of the switch body 18 which tends to urge the contact 42 into engagement with the fixed contact 38 while, at the same time, holding the cup-shaped actuator 50 in its operative position between the beveled flange 46 and an outer wall 58 of the switch body 18.

An insulating member 60 formed of elastomeric material, such as rubber, has an elongated cylindrical portion 62 and an outwardly projecting lip 64. The insulating member 60 is of slightly smaller diameter than the fixed contact 38 and the contact 42 and is stretched over these contacts substantially equidistant from their juncture point. A bellows portion 66, acting in an accordion fashion, allows the movement of the contact 42 away from the fixed contact 38 without disrupting their sealed engagement. During assembly, the outwardly projecting lip 64 of the insulating member 60 is pressed between the insulator plug 32 and the flange 34 to hold it in its operative position.

In the operation of the subject device, the switch body is threaded into a fluid carrying passage, generally by use of pipe threads, to prevent leakage past the threads from the pressure in the fluid carrying system. A typical environment might be the water cooling system of an internal combustion engine of the type used on automobiles. As water is caused to flow by the action of the pump 14 in the circulation line 16 in the direction of the arrows, the force of the water flowing in a portion 86 of the circulation line 16 will cause the cup-shaped actuator 50 to pivot on the beveled flange 46 with a con sequent tilting of one edge of the cup against the'outer wall 58 of the switch body 18. This pivoting action will draw the actuator rod 40 down through the aperture 44 against the tension of the spring 54 causing the contact 42 to be disengaged from the fixed contact 38. The fixed contact 38 being insulated from the switch body 18 will not continue to pass electrical current to the grounded movable contact 42. This will result in a breaking of the electrical circuit, previously described, to the indicating light 30. Thus, one monitoring the flow of the fluid in the circulation line 16 by viewing the indicating light 30 will be aware of the fact that fluid is flowing at a rate commensurate with the design of the switch.

It should be noted that, due to the slidable engagement of the actuator rod 40 with the aperture 44 and the mode' of mounting the switch, fluid will pass between the actuator rod 40 and the aperture 44 and enter the body of the switch surrounding the area in which the contacts are operating. However, due to the insulating member 60 surrounding the contacts 38 and 42, the switch will not be shorted during the circuit breaking function previously described. In addition, the bellows portion 66 will allow movement of the actuator rod away from the fixed contact 38 with very little hindrance and will also aid in the general alignment of the actuator rod in its movement. The spring retaining disk 52 is of suflicient diameter to prevent a severe cocking of the actuator rod during its movement.

Referring now to FIGURE 2, the switch structure is similar to that previously described except as hereinafter described. It should be noted that the reference numerals in the second embodiment are the same as those given in the first embodiment, illustrated in FIGURE 1, except where structural diflerences exist. In this embodiment, a cylindrical sleeve 68 has an outwardly projecting flange 70 which holds the cylindrical sleeve 68 in its operative position by being wedged between an insulator plug 32 and a flange 34 of the switch body 18. The cylindrical sleeve 68 has an aperture 72 in which the actuator rod 40 is disposed for sliding movement. The elastomeric seal 74 is held in its operative position by being wedged between a base 76 of the cylindrical sleeve 68 and a flange 78 of the switch body 18. The elastomeric seal 74 has a substantially sleeve-type portion 80 disposed in a retaining groove 82 of the actuator rod 40. An outwardly projecting lip 84 acts in much the same manner as a diaphragm during movement of the actuator rod 40 and provides a seal against moisture entering the switch body at the actuator end.

In operation, the embodiment described in FIGURE 2 is the same as that described for the embodiment in FIG- URE 1 except for the functioning of the seal 74. In this embodiment, described in FIGURE 2, the physical location of the seal is such that the area, in which the spring 54 as well as the fixed contact 38 and the movable contact 42 are contained, is moisture proof.

The utility of this invention becomes apparent in an application where the switch described is used to break a circuit to an indicating light which evidences the flow of water in an automobile cooling system. It is possible in the cooling systems of modern day automobile engines to have a restriction in circulation lines sufiicient to stop the flow of water while a pressure indication might still be had. In a typical installation, the subject device would be connected to an indicator lamp in the driving compartment of an automobile and, prior to engine start, when the ignition key is turned on, a light would indicate a noflow condition. As the engine was started, this indicating light would be extinguished, due to the circuit breaking function of the described switch, if the circulation of fluid in the cooling system was sufiicient to allow the safe operation of the engine. If such circulation was not had, the operator of the vehicle would be immediately apprised of the no-flow condition and could immediately stop the engine to prevent damage thereto that could normally ensue. This prompt apprisal could prevent great inconvenience to the operator of an automobile in that it could prevent the necessity of an engine shut down at a place remote from repair facilities.

Another and by no means secondary advantage to this type of arrangement is that very often an engine fan belt driving the water pump will break and an overheat condition will arise. Due to the ditferential rates of heating of various parts of the engine, it is possible that indication of such overheat condition through the normal means would not be given to the driver before overheating damage has already been done to parts of the engine not proximate to the temperature control.

Other obvious advantages of the present invention reside in the omnidirectional characteristics of the cupshaped actuator reposing in the fluid line and also the ability of the subject device to function while immersed in a conductive fluid, such as water.

While the embodiments of the present invention, as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. An electrical switch comprising, a body adapted to be disposed in a wall of a fluid passage, a plurality of conductive means disposed within said body, a first of said conductive means being fixed, a second of said conductive means being movable with respect to said first conductive means to selectively engage said first conductive means, an actuator means carried by said second conductive means and responsive to fluid flow to move said second conductive means into and out of engagement with said first conductive means, and a resilient sealing means encapsulating said conductive means and maintaining engagement therewith solely by its own resiliency and disposed to insulate said conductive means from fluid in the fluid passage.

2. An electrical switch responsive to fluid flow comprising, a switch body, first and second conductive means carried in said switch body in opposed juxtaposition, an actuator means extending from a first of said conductive means into a passage carrying fluid, said actuator means being carried by a first of said conductive means to selectively move said conductive means into and out of electrical engagement with a second of said conductive means in response to fluid flow, and a sealing means encapsulating said conductive means and maintaining engagement therewith solely by its own resiliency and being adapted to prevent fluid from the fluid passage from coming into contact with said first and second conductive means.

3. A fluid flow responsive electrical switch comprising, a body, a pair of contacts in said body being in opposed and adjacent juxtaposition and adapted to control the flow of electrical current therethrough, an actuator means carried by one of said contacts and suspended in a fluid passage, and a sealing means encapsulating said conductive means and maintaining engagement therewith solely by its own resiliency and being arranged to keep said pair of contacts free from the fluid in the fluid passage.

4. An electrical switch comprising a fixed contact, a movable contact in biased engagement with said fixed contact, an actuator means extending into a fluid passage from said movable contact and being arranged to selectively move said movable contact in and out of engagement with said fixed contact in response to fluid flow, and a sealing means encapsulating said conductive means and maintaining engagement therewith solely by its own resiliency and disposed between the fluid passage and said movable and said fixed contacts to keep said contacts free of fluid from the passage.

5. An electrical switch comprising, a body, a fixed contact disposed through one wall of said body, a movable contact disposed in biased engagement with said fixed contact together forming a conductive path for current flow, an actuator means slidably disposed through another wall of said body, said actuator means having one portion of substantially cupped shape disposed in a passage wherein fluid flows and another portion carrying said movable contact, and a sealing means disposed around said fixed contact and said movable contact, said sealing means having a bellows shaped portion at the point of engagement of said fixed contact and said movable contact to allow the free separation thereof, said cup-shaped actuator portion providing a flat plate area in said fluid passage thereby tending to resist fluid flow therein, said cup-shaped portion being levered by said fluid flow in the direction of flow thereby drawing said movable contact out of engagement with said fixed contact interrupting said path for current flow between said fixed and movable contacts.

6. An electrical switch comprising, a switch body, a fixed contact and a movable contact positioned within said body, said fixed contact being one end of a terminal extending through one wall of said body, an actuator means being biased away from another wall of said body and being slidable through the wall of said body in response to fluid flow, said actuator means having a portion of substantially cup shape disposed in a passage wherein fluid flows, and a sealing means arranged to prevent fluid entering said switch body at the point where the actuatormeans slidably moves through a wall of said body and coming into contact with said fixed and said movable contacts, said sealing means being yieldable to allow said movable contact to travel in and out of conductive engagement with said fixed contact.

7. An electrical switch comprising, a body having a threaded portion adapted to be mounted in a fluid passage, a terminal insulatedly mounted in one wall of said body and forming a fixed contact therein, an actuator means including a first end forming a contact and a second end slidably disposed through a wall of said body, said second end carrying a substantially cup-shaped member pivotally disposed in the fluid passage and ofiering a resistance to fluid flow therein, and a sealing means including a cylindrical sleeve wherein said fixed and movable contact means are disposed and being in conductive engagement with the walls of said body and having an aperture in one end thereof disposed to guide said actuator means during sliding movement of said actuator and an elastomeric member firmly engaged between said cylindrical sleeve and an outer wall of said body and a portion of the actuator means, said engagement maintining the area within said cylindrical sleeve free of fluid from said passage wherein said switch is mounted, said movable contact being levered out of engagement with said fixed contact as fluid flow in said passage urges said cup-shaped member in the direction of fluid flow.

References Cited by the Examiner BERNARD A. GILHEANY, Primary Examiner. 

1. AN ELECTRICAL SWITCH COMPRISING, A BODY ADAPTED TO BE DISPOSED IN A WALL OF A FLUID PASSAGE, A PLURALITY OF CONDUCTIVE MEANS DISPOSED WITHIN SAID BODY, A FIRST OF SAID CONDUCTIVE MEANS BEING FIXED, A SECOND OF SAID CONDUCTIVE MEANS BEING MOVABLE WITH RESPECT TO SAID FIRST CONDUCTIVE MEANS TO SELECTIVELY ENGAGE SAID FIRST CONDUCTIVE MEANS, AN ACTUATOR MEANS CARRIED BY SAID SECOND CONDUCTIVE MEANS AND RESPONSIVE TO FLUID FLOW TO MOVE SAID SECOND CONDUCTIVE MEANS INTO AND OUT OF ENGAGEMENT WITH SAID FIRST CONDUCTIVE MEANS, AND A RESILIENT SEALING MEANS ENCAPSULATING SAID CONDUCTIVE MEANS AND MAINTAINING ENGAGEMENT THEREWITH SOLELY BY ITS OWN RESILIENCY AND DISPOSED TO INSULATE SAID CONDUCTIVE MEANS FROM FLUID IN THE FLUID PASSAGE. 